Answer:
first : x²-10x=39
{-3;13}
second : multiply both sides by 1\4
last is : {-1;5}
Answer: A 13.4
Step-by-step
a^2 + b^2= c^2 4^2 + b^2 = 14^2 16+ b^2= 195 b^2= 180 b= square root of 180 b= 6 square root of 5 or 13.42
